Electric switch



P" 5,1927 n J. D; HILLIARD vELECTRI C SWITCH Filed Nov. 7, 1922 FigL I-nverwtoh: John D.Hillia1'-d by ww 27 41? His Attorhe' Patented Apr. 5, 1927.

UNITED STATES JOHN D. HILLIARD,

OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

-nnncrarc SWITCH.

Application filed November 17, 1922. Serial No. 601,636.

My invention relates to electric switches and especially to fluid break switches which have their conducting parts arranged to produce a magnetic field for blow ng out or extinguishing the are formed by the separation of the switch contacts under load.

In the usual construction of fluid break switches, the conducting circuit is arranged in the form of a loop, the stationary contacts and their connections to the switch terminals forming the sides and the straight bar interconnecting the movable contacts forming the bottom thereof. .Upon the flow of currentthrou h this loop, there is prduced a magnetic field which tends to blow out an are formed by the separation of the switch con tacts but which is ordinarily ineffective to produce this result because of its low intensity. The intensity of this field maybeincreased by reducing the spacing between the switch terminals but there is encountered the diificulty that thIs spacing cannot be reduced below a certain minimum because of the danger of arcing between the switch terminals.

An object of my invention, therefore, is to provide an arrangement of the switch circuit designed to greatly increase the rupturing capacity of the switch.

A further object of my invention isto provide improved means designed to intensify v the magnetic field of the switch for the purpose of quickly and effectively extinguishing an are formed by the separation of the switch contacts.

Other objects andadvantages will become apparent as my invention is considered in connection with the accompanying drawing in which Fig. 1 shows, partly in section and partly in elevation, a switch in which my invention has been embodied, and in which Fig. 2 shows a slightly different arrangement of the switch circuit.

Referring now to the drawing there is shown in Fig. 1 a switch tank 1 having an insulating lining 2 and a cover 3"in which is placed a valve 4 for permitting the escap: from the tank of any gases which may formed by volatilization of the insulating liquid 5 within which the switch contacts are immersed. The insulating bushings 6 which are arranged to support the terminals 7 and the stationary contacts 8 extend through and are supported by the tank cover 3. Clamping rings 9 are provided for rigidly securing the bushing 6 to the switch cover 3 and maintaining the stationary contacts 8 in operative relation with the movable contacts 10. The movable contacts 10 are supported and interconnected by a U-shaped bar or bridging member 11 which enters the tank 1 through a stufling box 13 and which may be reciprocated to open and close theswitch by any suitable operating means. The U-shaped member 11 is provided with insulation 14 for the purpose of localizing at the switch contacts any are which may be formed between them as a result of their separation when the switch is loaded.

As shown in Fig. 1, the conductingcircuit of the switch is'arranged in the form of a double loop, the spacing between the loop sides in this case being much smaller than is permissible in the usual construction where the movable electrodes are interconnected by .a straight bridging member. This reduction in the spacing between the loop sides mate rially strengthens the disrupting force exerted by the magnetic field of the switch upon an are between the switch terminals and thus operates to greatly increase the rupturing capacity of the switch.

The modification shown in Fig. 2 diflers from that shown in Fig. 1 in that the bridging member which interconnects the movable contacts is formed into a number of turns 15 for the purpose of intensifying the magnetic field at the switch contacts. As actually constructed, the turns of this bridging member are preferably wound in the form of a pancake coil which is provided with insulation for the pur ose of localizing the are at the contacts 0 the switch. In the diagrammatic showing of Fig. 2 the turns 15 are spaced sidewise from each other merely to show the coil construction more clearly. I

My invention may be embodied in other forms than that shown and described and I, therefore, intend to cover by the appended claims all changes and modifications apparent to those skilled in the art and within the scope of my invention.

What I claim as new and desire by Letters Patentof the United States, is

1. A fluid switch com rising stationary and movable contacts, an a bridging member interconnectin said movable contacts, said bridging member being provided with fixed to the operating rod 12 l0 porting member being lation to localize at the switch contacts an are formed by the opening of the switch, and being comprised of a portion forming in effect a loop with said stationary Contact to intensify the magnetic field at the switch contacts whereby an are formed by the opening of the switch is disrupted.

In witness whereof, I have hereunto set my hand this 16th day of November, 1922.

JOHN D. 'HILLIARD. 

